Preheat the oven to 350°F (177°C) and place the rack in the lower third. Grease your loaf pan thoroughly to prevent sticking. Proper preparation ensures even baking and easy removal after baking.
In a bowl, whisk together flour, baking soda, salt, and cinnamon. Mixing them first helps distribute the leavening evenly. This step ensures consistent texture in every slice.
In a large bowl, beat softened butter and brown sugar until light and creamy. Add eggs one at a time, mixing well after each addition. Then blend in yogurt, vanilla, and mashed bananas until smooth and combined.
Add the dry ingredients to the wet mixture and mix on low speed just until combined. Avoid overmixing to keep the bread soft and tender. Pour batter into the prepared pan and bake for 60–65 minutes, loosely covering with foil halfway through to prevent over-browning.
Insert a toothpick in the center to check doneness — it should come out clean with a few moist crumbs. Allow the bread to cool in the pan for about one hour. Remove carefully, slice, and enjoy.